A continuous catalytic system for biodiesel production

Adipose deposition and Barrett’s esophagus: Is all fat created equal?

The presence of the tumor in women with breast cancer provokes a profile of biochemical change characterized by hypoglycemia, hyperuremia and high levels of free fatty acids and ketone bodies in plasma. The total circulating levels of amino acids and lactate are slightly higher in patients with breast cancer. Moreover, alterations in the circulating levels of free and total fatty acids are associated with enhanced levels of total free fatty acids and significantly lower levels of esterified arachidonic acid. This profile may indicate a state of moderate catabolic activation in breast cancer patients and may also be associated with a slight mobilization of proteins and fatty acids by some of the peripheral tissues in order to cover the needs of the host and the tumor. However, the alteration in the distribution of different fatty acids (saturated, mono-unsaturated and poly-unsaturated) and the different behaviour of the free and esterified fractions may be the result of a greater release of only specific fatty acids by tumor or other host tissues, rather than a higher release of the whole spectrum of free fatty acids. Thus, it is proposed that some of the alterations may be directly related to localized tumor activity.

The level of free fatty acids in intact tissues has been found to be low but is known to rise in proportion to the extent of autolysis. Therefore, the high levels of free fatty acid reported in the cardiac lipids of rats fed rapeseed oil were reinvestigated using two different procedures for homogenization. Quick freezing and pulverization at dry ice temperature followed by lipid extraction was found to give lower values of free fatty acids (200 microgram/g of wet heart tissue) than the more commonly used technique of employing rotating blade-type homogenizers (greater than 1700 microgram/g of wet heart tissue). The amount of diglycerides was found to be 3 times greater when the latter method was used. The high levels of free fatty acid and diglyceride suggest that extensive autolysis occurs during homogenization with a rotating blade-type homogenizer. Freezing and pulverization at dry ice temperature is therefore recommended for determining intact lipid classes in rat heart.

The lymphoid cells from thymus, spleen or mesenteric lymph node of mice treated with hydrocortisone or cyclophosphamide contained the significantly high levels of free fatty acids, triglycerides and cholesterol esters as compared to the corresponding cells from untreated animals.

BackgroundType 2 diabetes (T2D) is a strong risk factor for developing neurodegenerative pathologies. T2D patients have a deficiency in the intestinal incretin hormone GLP-1, which has been shown to exert neuroprotective and anti-inflammatory properties in the brain.MethodsHere we investigate potential sources of GLP-1 in the CNS and the effect of diabetic conditions on the proglucagon mRNA expression in the CNS. The obese mouse model ob/ob, characterized by its high levels of free fatty acids, and the microglia cell line BV-2 were used as models. mRNA expression and protein secretion were analyzed by qPCR, immunofluorescence and ELISA.ResultsWe show evidence for microglia as a central source of GLP-1 secretion. Furthermore, we observed that expression and secretion are stimulated by cAMP and dependent on microglial activation state. We also show that insulin-resistant conditions reduce the central mRNA expression of proglucagon.ConclusionThe findings that microglial mRNA expression of proglucagon and GLP-1 protein expression are affected by high levels of free fatty acids and that both mRNA expression levels of proglucagon and secretion levels of GLP-1 are affected by inflammatory stimuli could be of pathogenic importance for the premature neurodegeneration and cognitive decline commonly seen in T2D patients, and they may also be harnessed to advantage in therapeutic efforts to prevent or treat such disorders.

The effects of acute hypertriglyceridemia and high levels of free fatty acids on left ventricular function

Critical illness and severe inflammation are catabolic states characterised by breakdown of tissue and protein stores, by increased levels of free fatty acids, and by insulin resistance. These metabolic features contribute to morbidity and mortality. Growth hormone and insulin are the two major anabolic hormones. The present study was designed to test whether increased levels of free fatty acids (i) inhibit growth hormone secretion and (ii) induce insulin resistance during acute endotoxin exposure in a porcine model of critical illness. We studied 20 pigs for 6 h during combined anaesthesia and endotoxin infusion and a hyperinsulinaemic glucose clamp to control glucose, insulin, and free fatty acid concentrations. Pigs were randomised to two different continuous infusion rates of Intralipid resulting in different, sustained, and elevated free fatty acid concentrations (1.63 mmol l(-1) vs. 0.58 mmol l(-1), p=0.0002). Concomitantly, we observed reduced growth hormone concentrations in the group with high free fatty acid concentrations (3.5 ng ml(-1) vs. 6.6 ng ml(-1), p<0.003). No difference in insulin sensitivity, measured as the glucose infusion rate necessary to maintain euglycaemia, was observed. We conclude that high levels of free fatty acids reduce circulating growth hormone concentrations in porcine endotoxaemia; this probably constitutes a negative feedback mechanism whereby growth hormone induced-stimulation of free fatty acids release inhibit growth hormone secretion. This mechanism may further contribute to protein loss in critical illness. We found no evidence that the increment of plasma free fatty acids between groups contribute to insulin resistance in critical illness.

One of the important inducers of inflammatory responses and accumulation of fat in hepatocytes is free fatty acids which ultimately lead to the development of non-alcoholic fatty liver disease. Patients with non-alcoholic fatty liver disease have high levels of plasma free fatty acids which are usually associated with type 2 diabetes and components of metabolic syndrome including dyslipidemia. Objective of this research is to investigate the effects of orlistat (a lipase enzyme inhibitor) or telmisartan (an angiotensin receptor blocker) on the serum free fatty acids in non-alcoholic fatty liver disease patients taking into consideration the baseline lipid profile. This open-label clinical trial was carried out in the Department of Pharmacology, College of Medicine at the University of Sulaimani in cooperation with Shar Teaching Hospital in Sulaimani city-Kurdistan Region of Iraq. A total number of 74 non-alcoholic fatty liver disease patients were recruited and grouped randomly into group I (n = 25) treated with orlistat (120 mg/day orally) for 12 weeks, group II (n = 24) treated with telmisartan (20 mg/day orally) for 8 weeks, and group III (n = 25) treated with placebo (carboxy- methyl cellulose) once daily. Fasting serum level of free fatty acid and lipid profile including total cholesterol, triglyceride, high-density lipoprotein, and non-high-density lipoproteins were determined. Orlistat and telmisartan significantly reduced the triglyceride-glucose index and free fatty acid levels (P < .001) in patients with non-alcoholic fatty liver diseases. Short-term treatment with orlistat or telmisartan produce effective and significant reductions in FFAs in patients with non-alcoholic fatty liver disease compared to placebo. Orlistat effectively reduces the free fatty acid irrespective of the baseline lipid profile.

Adrenergic effects on plasma levels of glucagon, insulin, glucose and free fatty acids were studied in fasted rabbits by infusing epinephrine, norepinephrine, isoproterenol, phentolamine (an adrenergic alpha-receptor blocking drug) and propranolol (an adrenergic beta-receptor blocking drug). The adrenergic effects on the plasma levels of insulin, glucose and free fatty acids were similar to those found in other species. The plasma levels of insulin were increased by beta-receptor stimulation (isoproterenol, phentolamine + epinephrine) and decreased by alpha-receptor stimulation (epinephrine, norepinephrine, propranolol + epinephrine). The plasma levels of glucose were increased by both alpha- and beta-receptor stimulation, and the epinephrine-induced hyperglycaemia was only blocked by combined infusions with phentolamine and propranolol. The plasma levels of free fatty acids were increased by saline and further increased by beta-receptor stimulation (isoproterenol), while epinephrine and norepinephrine gave variable results. Alpha-receptor stimulation (propranolol + epinephrine) slightly decreased the plasma levels of free fatty acids. The plasma levels of glucagon, however, were mainly increased by alpha-receptor stimulation (epinephrine, norepinephrine, propranolol + epinephrine) and increased only to a minor extent by beta-receptor stimulation (isoproterenol, phentolamine + epinephrine) in rabbits. This is in contrast to results reported for humans, where beta-receptor stimulation seems to be most important in stimulating glucagon release.

High levels of free fatty acids have emerged as a major link between obesity and insulin resistance/Type 2 diabetes. In pancreatic β cells, free fatty acids potentiate glucose-stimulated insulin secretion precisely to the extent needed to compensate for the free fatty acid-induced insulin resistance. It is postulated that this prevents the development of Type 2 diabetes mellitus in the majority of obese, insulin-resistant individuals who have free fatty acid-mediated insulin resistance. In individuals with inherited defects of β-cell function (prediabetics), this compensation fails and hyperglycemia develops. Elevated levels of free fatty acids also activate the proinflammatory and proatherogenic nuclear factor κB pathway. Thus, elevated plasma levels of free fatty acid in obese people can produce a low-grade inflammatory state, which may contribute to accelerated atherosclerosis (coronary artery disease, strokes and peripheral arterial disease) and to nonalcoholic steatohepatitis; these conditions are increased in obesity.

Intravenous lipid emulsions are commonly used as a part of parenteral nutrition in premature infants. The potential bilirubin-displacing effects of high free fatty acid (FFA) levels during lipid infusions are known. Levels of free bilirubin (FB) predict the risk of bilirubin neurotoxicity more accurately than indirect serum bilirubin levels. In the present study, we decided to compare the effect of two different lipid solutions on free bilirubin and free fatty acids levels in premature infants. Infants were grouped into two groups according to intravenous lipid preparations: Infants in Group 1 received lipid emulsion containing olive oil + soybean oil and Group 2 received containing olive oil + soybean oil + fish oil. The blood samples were gained when lipid intake was 3.5 g/kg/day and FFA and FB levels were analyzed. Serum FFA and FB levels were similar in groups (p = 0.26 and 0.69 respectively). There were significant correlation between serum FFA and FB levels in Group 1 (r = 0.74, p < 0.001) and in Group 2 (r = 0.92, p < 0.001). Both lipid preparations seem to have similar effects on free bilirubin and free fatty acid levels in premature newborns.

BACKGROUNDThe increasing value of pure vegetable oils has made the use of waste cooking oils an attractive alternative feedstock for biodiesel production but the presence of free fatty acids in the waste significantly reduces efficiency of the conversion.RESULTSA low‐temperature mixed ionic liquid system with dual extraction and catalytic functions for the conversion of waste oils containing high levels of free fatty acids to biodiesel was successfully trialled. The solvent, a totally miscible system of HPyrBr and the Brønsted acid, SPyrHSO4, allows the key properties of each ionic liquid, as extractant or catalyst, to work uninhibited by the presence of the other. Extraction of free fatty acids from vegetable oils and their conversion to methyl esters in high yield is demonstrated for vegetable oils, containing single and mixed fatty acids, and for a model waste cooking oil. The oil separated from free fatty acids in the waste has a low acid value and can be converted efficiently to biodiesel; with the ionic liquid solvent recovered unchanged for reuse.CONCLUSIONSA mixed ionic liquid extraction‐esterification solvent process has been developed to effect efficient conversion of free fatty acids in waste vegetable oils to biodiesel and their conversion to esters. © 2017 Society of Chemical Industry

Objectives: The objectives of this study were to evaluate the clinical and nutritional correlates of high free fatty acids (FFAs) level in critically ill patients and the association with outcomes, and to study the effect of short-term caloric restriction (permissive underfeeding) on FFAs level during critical illness. Patients/Method: In this pre-planned sub-study of the PermiT (Permissive Underfeeding vs. Target Enteral Feeding in Adult Critically Ill Patients) trial, we included critically ill patients who were expected to stay for ≥14 days in the intensive care unit. We measured FFAs level on day 1, 3, 5, 7, and 14 of enrollment. Of 70 enrolled patients, 23 (32.8%) patients had high FFAs level (baseline FFAs level >0.45 mmol/L in females and >0.6 mmol/L in males). Results: Patients with high FFAs level were significantly older and more likely to be females and diabetics and they had lower ratio of partial pressure of oxygen to the fraction of inspired oxygen, higher creatinine, and higher total cholesterol levels than those with normal FFAs level. During the study period, patients with high FFAs level had higher blood glucose and required more insulin. On multivariable logistic regression analysis, the predictors of high baseline FFAs level were diabetes (adjusted odds ratio (aOR): 5.36; 95% confidence interval (CI): 1.56, 18.43, p = 0.008) and baseline cholesterol level (aOR, 4.29; 95% CI: 11.64, 11.19, p = 0.003). Serial levels of FFAs did not differ with time between permissive underfeeding and standard feeding groups. FFAs level was not associated with 90-day mortality (aOR: 0.49; 95% CI: 0.09, 2.60, p = 0.40). Conclusion: We conclude that high FFAs level in critically ill patients is associated with features of metabolic syndrome and is not affected by short-term permissive underfeeding.

Changes in Plasma Free Fatty Acids and Triglycerides in Dairy Cattle After Dosing with Coffee or Caffeine

The main objective of this study was to determine whether the excitotoxic cholinesterase inhibitor soman increases the catabolism of phospholipids in rat brain. Injections of soman (70 micrograms/kg, s.c.), at a dose that produced toxic effects, increased the levels of both free fatty acids (175-250% of control) and free choline (250% of control) in rat cerebrum 1 h after administration. All fatty acids contained in brain phosphatidylcholine were elevated significantly including palmitic (16:0), stearic (18:0), oleic (18:1), arachidonic (20:4), and docosahexaenoic (22:6) acids. The changes observed were consistent with those reported to occur following ischemia and the administration of other convulsants. Pretreatment of rats with the anticonvulsant diazepam (4 mg/kg, i.p.) prevented both the signs of soman toxicity and the soman-induced increase of choline and free fatty acids. Diazepam alone did not affect the levels of choline or free fatty acids, cholinesterase activity, or soman-induced cholinesterase inhibition, suggesting that soman toxicity involves a convulsant-mediated increase in phosphatidylcholine catabolism. In addition, administration of the convulsant bicuculline, at a dose that produces seizures and increases the levels of free fatty acids in brain, significantly increased the levels of choline. Results suggest that excitotoxic events enhance the hydrolysis of phosphatidylcholine in brain as evidenced by a concomitant increase in the levels of choline and free fatty acids.